Mathematical modelling of the Dengue transmission with waning immunity and controls

A mathematical model of dengue transmission involving a host–vector interaction was developed, incorporating human vaccination with imperfect (leaky) and waning protection. Both disease-free and endemic equilibria were characterised. Using the next-generation method, the control reproduction number, Rcv, was derived. Centre manifold analysis revealed that a backward bifurcation occurs when the bifurcation coefficient a>0, indicating that multiple endemic equilibria may exist when Rcv<1. The global asymptotic stability of the endemic equilibrium was proven under certain conditions. Global sensitivity analysis identified key drivers in the model, such as; mosquito biting, recruitment rates, human-to-mosquito and mosquito-to-human transmission probabilities, human treatment rate, mosquito mortality, and vaccine efficacy to be the most influential parameters in the dynamics of dengue transmission. Numerical experiments show that significant gains could be achieved by combining high-efficacy vaccination with adequate coverage, vector control, and timely treatment. Based on this study, it is crucial to implement integrated strategies that combine high-efficacy vaccination, vector control, and timely treatment. Special attention should be paid to maintaining adequate vaccination coverage, especially in settings where vaccine efficacy wanes over time.